Controlling samba access by interface

[Michael Hipp]

I have a samba server with 3 interfaces (eth0,1,2). Different types of 
people connect to the different interfaces. Some are trusted and some 
are not. I'd like the untrusted group to have access to only certain 
shares while the trusted group has access to all shares. Using passwords 
is really not an option as the trusted group has a "Public" share with 
wide open security but I don't want the untrusted group to even be able 
to see it.

The only way I can find to do this is by running multiple instances of 
Samba and using the "interfaces = eth0" option in smb.conf to bind each 
instance to a different eth.

Is there some other way? Anyone tried running multiple instances of 
samba on 1 box?

Thanks,
Michael